1. Field of the Invention:
The present invention relates to an apparatus for recording and/or reproducing a PCM audio signal by using a rotary head.
2. Description of the Prior Art:
A standardization for the so-called 8 mm video tape recorder has been set internationally. With such standardization, recording and/or reproducing are carried out by a pair of rotary heads provided with an angular spacing of 180.degree. therebetween, and a tape is wrapped around 221.degree. of the rotational circumferential surface of the rotary heads. In a 180.degree. interval of the 221.degree., a video signal is recorded and/or reproduced, while a PCM audio signal with a compressed time base is recorded and/or reproduced in the interval of the remaining 36.degree..
FIG. 1 shows a format of a recording track on a tape according to the above mentioned standardization. From the right-hand side at which the head begins to contact with the tape, at the tip end of the track there is provided a tracing start area 51 of 5.degree. of a rotation angle of the head. At the next or rear portion of the tracing start area 51, over 2.06.degree. (corresponding to 3 horizontal intervals (H) of a video signal), there is provided a clock run-in area 52 which is synchronized with succeeding PCM data. Next to the clock run-in area 52, there is provided a PCM data area 53 over 26.32.degree. for use with an audio signal with a compressed time base. A period or area of 2.06.degree. (3H) next to the data area 53 is assigned as a back margin area 54 for coping with the erroneous displacement of the recording position. The back margin area is followed by a guard area 55 of 2.62.degree. between a video area and a PCM data area. Next to the guard area 55, there is provided a video signal area 56 for one field over 180.degree.. Furthermore, the video signal area is followed by a head detaching area of 5.degree..
Accordingly, in this standardization, the video signal of one field is recorded on and reproduced from the video signal area 56. At the same time, an audio signal of 1/60 second is pulse code modulated, processed for error correction or the like, then time base compressed to about 1/6.8, and is recorded on and reproduced from the PCM data area 53. This recording track is sequentially and obliquely formed along the longitudinal direction of the tape, by which the continuous video and audio signals are recorded and/or reproduced.